An extended knowledge intervention addressing vaccine hesitancy in the field: Results from two representative surveys

Older adults may fail to demand influenza and pneumococcal vaccinations due to limited knowledge of its role in preventing initial influenza infections, secondary complications such as pneumonia, and serious late consequences such as sepsis. We evaluated the extended health knowledge approach during the field intervention "Vaccination60+" to determine whether providing this additional information could improve vaccination among older adults.

The intervention was implemented in a model region in Germany during two influenza seasons. Two quota-sampled telephone surveys targeting adults 60+ were conducted to evaluate the extended health knowledge approach in an intervention (N = 700 each). Quasi-experimental groups were defined based on whether participants recalled the intervention (intervention-exposed vs. nonexposed). Knowledge (influenza, pneumococci, and sepsis), the 5 °C antecedents of vaccination, and vaccination intention and behavior were assessed.

Intervention exposure was associated with higher knowledge about influenza (η² = .009), pneumococci (η2 = .012), and sepsis (η² = .004). It was also associated with higher risk-benefit calculation regarding influenza vaccination (η² = .003) and increased confidence in the safety of pneumococcal vaccination (η² = .020). Vaccination intentions for both diseases did not differ according to exposure. Vaccination behavior increased over time, (influenza: OR = 1.88; pneumococci: OR = 2.08), potentially due to external factors that are discussed.

Providing information can support health decisions and relate to higher risk awareness but may not alter actual behavior. Further recommendations regarding vaccination interventions (e.g., provider endorsement, tailoring to prior knowledge) that could decrease hesitancy are discussed. (PsycInfo Database Record (c) 2026 APA, all rights reserved).